TWI481651B - (meth) acrylate-styrene based copolymer composition and the molding product thereof - Google Patents

Description

(Meth)acrylate-styrene copolymer composition and its formation Model

The present invention relates to a (meth) acrylate-styrene copolymer composition, and more particularly to a (meth) acrylate-styrene copolymer comprising an inner ring bisphenol phosphite compound. Things.

The poly(meth) acrylate has good processing, physical properties and mechanical properties, and the obtained molded article has a light transmittance of 92%, which is superior to glass and has low birefringence, and the molded article has a good appearance. One of the most excellent polymer transparent materials. Poly(meth)acrylate is also known as "plexiglass" and is often used as a variety of optical components or consumer products such as camera lenses, lenses, automotive taillights, billboards, and the like. However, although poly(meth)acrylate has excellent optical properties and process formability, water absorption and heat stability are somewhat insufficient.

Although polystyrene has good water absorption and thermal stability, it has poor weather resistance and may cause coloring or mechanical property degradation under long-time illumination.

The (meth) acrylate-styrene copolymer obtained by polymerizing styrene and (meth) acrylate as a main raw material, in addition to the advantages of combining polystyrene and poly(meth) acrylate, Improve the shortcomings of the two polymers. However, in order to meet the nature requirements of each application, how to design (A The content range of the (meth) acrylate monomer unit and the styrene monomer unit in the acrylate-styrene copolymer is another problem to be solved.

In addition to the design of the content range of the (meth) acrylate monomer unit and the styrene monomer unit, in view of the demand for various optical products, it is currently desired to further improve the (meth) acrylate-styrene copolymer. The properties of the resulting molded article in terms of optical properties (eg, chromaticity, luminance, and penetration). From this, it can be seen how the molded article obtained by the (meth) acrylate-styrene copolymer has the advantages of both polystyrene and poly(meth) acrylate (such as excellent transparency, optical properties, and weather resistance). It has good properties, easy processing, small residual stress of molded products, low water absorption, good thermal stability, etc. It has low yellowness, high brightness and high penetration, which is also the focus of development in this technical field.

Accordingly, a first object of the present invention is to provide a (meth) acrylate-styrene copolymer composition which has the advantages of both polystyrene and poly(meth) acrylate.

The (meth) acrylate-styrene copolymer composition of the present invention comprises a (meth) acrylate-styrene copolymer and an inner ring bisphenol phosphite compound. The (meth) acrylate-styrene copolymer, comprising 40% by weight to 70% by weight of (meth) acrylate monomer units, and 30% by weight to 60% by weight of styrene monomer units . The inner ring bisphenol phosphite compound has a structure represented by the following formula (I): In the formula (I), R ¹ to R ⁴ each independently represent a C ₁ to C ₁₀ linear alkyl group or a C ₁ to C ₁₀ branched alkyl group, and R ⁵ represents a C ₁ to C ₃₀ linear alkyl group. or a C ₁ to C ₃₀ branched alkyl, R ⁶ is represented by H, C ₁ to C straight chain alkyl group or C ₄ branched alkyl group of ₁ to C _4. The content of the inner ring bisphenol phosphite compound is from 0.01 to 0.3 parts by weight based on 100 parts by weight of the total of the (meth) acrylate-styrene copolymer.

A second object of the present invention is to provide a molded article.

The molded article of the present invention is formed from the above (meth)acrylate-styrene copolymer composition.

The effect of the present invention is that the (meth) acrylate-styrene copolymer comprises 40% by weight to 70% by weight of (meth) acrylate monomer units, and 30% by weight to 60% by weight of benzene. a vinyl monomer unit having the advantages of both polystyrene and poly(meth) acrylate, and at the same time, by an internal ring bisphenol phosphite compound in an amount ranging from 0.01 to 0.3 parts by weight, The molded article obtained from the acrylate-styrene copolymer composition has the advantages of low yellowness, high luminance, high transparency, low mold contamination, good mechanical strength, and good thermal stability.

Herein, the (meth)acrylate [(meth)acrylate] means acrylate and/or methacrylate.

The (meth)acrylate-styrene copolymer composition of the present invention comprises a (meth)acrylate-styrene copolymer and an inner ring bisphenol phosphite compound.

The melting coefficient of the (meth) acrylate-styrene copolymer composition ranges from 1.2 g/10 min. to 2.4 g/10 min. (melting coefficient measurement conditions: temperature 200 ° C, load 5 kg), and has good Processability. The (meth) acrylate-styrene copolymer composition has a softening point temperature in the range of 100 ° C to 110 ° C and has good thermal stability.

Hereinafter, each component of the (meth) acrylate-styrene copolymer composition of the present invention will be further described as follows:

[(Meth)acrylate-styrene copolymer]

The (meth) acrylate-styrene copolymer includes 40% by weight to 70% by weight of a (meth) acrylate monomer unit, and 30% by weight to 60% by weight of a styrene monomer unit. Preferably, the (meth) acrylate-styrene copolymer comprises 40% by weight to 50% by weight of a (meth) acrylate monomer unit, and 50% by weight to 60% by weight of a styrene system. Monomer unit. When the styrene monomer unit is less than 30% by weight, that is, the (meth) acrylate monomer unit content is more than 70% by weight, the (meth) acrylate-styrene copolymer composition The hygroscopicity is high, and the dimensional stability of the subsequently obtained molded article is poor; when the styrene monomer is super When the content of the (meth) acrylate monomer unit is less than 40% by weight, the weather resistance of the (meth) acrylate-styrene copolymer composition is poor, so that it is subsequently produced. The molded article has a problem of coloring and mechanical property degradation under long-time illumination.

The (meth) acrylate-styrene copolymer has a weight average molecular weight ranging from 100,000 to 200,000, more preferably from 130,000 to 170,000. The (meth) acrylate-styrene copolymer has a glass transition temperature in the range of from 100 ° C to 110 ° C, more preferably from 102 ° C to 108 ° C.

A styrene monomer for polymerizing the (meth) acrylate-styrene copolymer is, for example but not limited to, styrene or substituted styrene. The substituted styrenes are, for example, (1) halogen-substituted styrenes such as chlorostyrene or bromostyrene; (2) vinyl toluene or α-methylstyrene (α- Methylstyrene) is an alkyl substituted styrene.

The (meth) acrylate monomer used for polymerizing the (meth) acrylate-styrene copolymer is, for example but not limited to: (1). methacrylate: ethyl methacrylate, methyl Butyl acrylate, cyclohexyl methacrylate, octadecyl methacrylate, phenyl methacrylate, benzyl methacrylate or 2-ethylhexyl methacrylate (2). Acrylates: methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate or 2-ethylhexyl acrylate, etc. (3). Unsaturated carboxylic acid or its anhydride: acrylic acid, methacrylic acid, maleic acid or clothing (itaconic acid), etc.; (4) hydroxyl group-containing (meth) acrylates: acrylic acid monoglyceride or 2-hydroxyethyl (meth)acrylate, etc.; (5) Other propylene-containing compounds: acrylamide, acrylonitrile, allyl glycidyl ether or glycidyl (meth)acrylate [glycidyl ( Meth)acrylate]etc.

The (meth) acrylate-styrene copolymer can be produced by a solution polymerization method or a bulk polymerization method, and it is preferred to carry out a polymerization reaction in the presence of a solvent. The boiling point of the solvent is preferably similar to the boiling point of the main monomer used for the polymerization reaction, for example, a solvent having a boiling point close to the boiling point of the (meth) acrylate monomer or the styrene monomer is selected to make the solvent and the above single The mixture formed by the body has a narrow boiling point range, which reduces the chance of the mixture mixing into the contaminant during the recycle, eliminating the need for intermediate fractionation of the mixture. Preferably, the solvent has a boiling point in the range of from 40 ° C to 225 ° C, more preferably from 60 ° C to 180 ° C. More specifically, the solvent is a hydrocarbon solvent or an aromatic hydrocarbon solvent having a boiling point range as described above, and can be used singly or in combination, and specific examples of the solvent include, but are not limited to, hexane, heptane, and octane. , benzene, toluene, p-xylene, o-xylene, m-xylene, ethylbenzene, cyclohexane, cyclodecane or isooctane.

The polymerization reaction of the (meth) acrylate-styrene copolymer is initiated by a radical initiator, which is not particularly limited, and can be used singly or in combination. Specific examples of the radical initiator are, for example but not limited to: (1) azo compounds: 2,2'-Azobis-(isobutyronitrile, AIBN for short), 2,2'-azo two (2-methylbutyronitrile) [2,2'-Azobis-(2-methylbutyronitrile), abbreviated as AMBN] or 2,2'-azobis(2,4-dimethylvaleronitrile) [2,2' -Azobis-(2,4-dimethylvaleronitrile), abbreviated as ADVN], etc.; (2) Diacyl peroxides: dilauroyl peroxide, decanoyl peroxide Or dibenzoyl peroxide (BPO), etc.; (3) Dialkyl peroxides: 2,5-dimethyl-2,5-di (tertiary butyl Oxy)hexane [2,5-dimethyl-2,5-di-(t-butylperoxy)hexane], dicumyl peroxide or 1,3-bis(tri-butyl peroxyisophthalate) Propyl) benzene [1,3-bis-(t-butyl peroxy isopropyl)benzene]; (4) Peroxyesters: tert-butyl peroxypivalate Or 2,5-dimethyl-2,5-di(2-ethylhexanolperoxy)hexane [2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane]; 5). Peroxycarbonates: tert-amylperoxy 2-ethylhexyl carbonate Tert-butylperoxy 2-ethylhexyl carbonate, etc.; (6) Peroxydicarbonates: dimyristyl peroxydicarbonate Peroxydicarbonate) or di(4-tert-butylcyclohexyl)peroxydicarbonate, etc.; (7) Peroxyketal compound: 1,1 -2 (tertiary butyl peroxy)-3,3,5-trimethylcyclohexane [1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane] or 2,2-di ( 4,4-di (tertiary butyl Oxidation of cyclohexyl)propane [2,2-di(4,4-di(tert-butylperoxy)cyclohexyl)propane]; (8). Hydroperoxides: tert-butyl hydroperoxide ( t-Butyl hydroperoxide) or isopropylcumyl hydroperoxide; (9). Other: 2,3-dimethyl-2,3-diphenylbutane (2,3- Dimethyl-2,3-diphenyl butane), Potassium persulfate, sodium persulfate or Ammonium persulfate. The radical initiator is used in an amount of from 0.01 to 1 part by weight, preferably from 0.03 to 0.5 part by weight, more preferably from 0.07 to 0.1 part by weight, based on 100 parts by total of the monomer mixture fed. .

The polymerization reaction of the (meth) acrylate-styrene copolymer can be carried out at normal temperature, and the reaction system can be heated to increase the rate of polymerization. The reaction temperature of the polymerization reaction of the (meth) acrylate-styrene copolymer is in the range of 25 ° C to 200 ° C, preferably 50 ° C to 180 ° C. The polymerization time of the (meth) acrylate-styrene copolymer is from 6 hours to 10 hours.

[Internal ring bisphenol phosphite compound]

The inner ring bisphenol phosphite compound has a structure represented by the following formula (I):

In the formula (I), R ¹ to R ⁴ each independently represent a C ₁ to C ₁₀ linear alkyl group or a C ₁ to C ₁₀ branched alkyl group, and R ⁵ represents a C ₁ to C ₃₀ linear alkyl group. or a C ₁ to C ₃₀ branched alkyl, R ⁶ is represented by H, C ₁ to C straight chain alkyl group or C ₄ branched alkyl group of ₁ to C _4.

More specifically, R ¹ to R ^{4 are,} for example but not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, tert-butyl, isobutyl, n-pentyl, A tertiary pentyl group, a hexyl group, a heptyl group, an octyl group, an isooctyl group, a 2-ethylhexyl group, a tertiary octyl group, a decyl group or a tertiary fluorenyl group is preferably a tertiary butyl group. R ^{5 is,} for example but not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, tert-butyl, isobutyl, n-pentyl, tertiary pentyl, hexyl, g. Base, octyl, isooctyl, 2-ethylhexyl, trioctyl, decyl, tertyl fluorenyl, fluorenyl, isodecyl, dodecyl, tetradecyl, hexadecyl, Octadecyl, eicosyl, behenyl, tetracosyl or tridecyl, etc., preferably octyl. R ^{6 is,} for example but not limited to, hydrogen, methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, tert-butyl or isobutyl. Preferably, R ⁶ is hydrogen.

In an embodiment of the invention, the inner ring bisphenol phosphite compound is 2,2'-methylenebis(4,6-ditributylphenyl)octylphosphite [2,2 '-methylene-bis-(4,6-di-tert-butylphenyl)octyl phosphite].

The content of the inner ring bisphenol phosphite compound is from 0.01 to 0.3 parts by weight based on 100 parts by weight of the total of the (meth) acrylate-styrene copolymer. It is preferably from 0.01 to 0.15 parts by weight, more preferably from 0.04 to 0.12 parts by weight. High temperature process leads to (meth) acrylate-styrene The molded article obtained by the copolymer composition is yellowed. Therefore, when the content of the inner ring bisphenol phosphite compound is less than 0.01 parts by weight, the above phenomenon cannot be effectively improved, so that the yellowness of the subsequently obtained molded article is partial. high. On the other hand, when the inner ring bisphenol phosphite compound exceeds 0.3 parts by weight, the effect of improving the above phenomenon is limited, that is, the effect corresponding to the amount of use of the inner ring bisphenol phosphite compound cannot be obtained.

Preferably, the oligomer (oligomer) content of the (meth) acrylate-styrene copolymer composition ranges from 500 ppm to 5000 ppm, preferably from 1000 ppm to 4000 ppm, more preferably 1500. Ppm to 3500 ppm. When the content of the oligomer exceeds 5,000 ppm, the long-path yellowness of the (meth)acrylate-styrene-based copolymer composition is deteriorated and mold contamination is likely to occur at the time of injection molding.

[additive]

The (meth) acrylate-styrene copolymer composition of the present invention may optionally further contain an additive, such as, but not limited to, a plasticizer, a processing aid, or the like, without impairing the effects of the present invention. UV stabilizer, UV absorber, antioxidant, filler, reinforcing agent, coloring agent, slip agent, antistatic agent, flame retardant, flame retardant, thermal stabilizer, thermal discoloration inhibitor, coupling agent or other Additives and the like, the above additives are not limited to being added during the polymerization reaction, after the polymerization reaction, before the coagulation or during the kneading.

The antioxidant may be used singly or in combination, and is not limited thereto, for example, a phenol-based antioxidant, a thioether-based antioxidant, or a phosphorus-based antioxidant. The total amount of the (meth) acrylate-styrene copolymer is 100 parts by weight. The antioxidant is contained in an amount of 0.005 to 2.0 parts by weight.

Specific examples of phenolic antioxidants are: 3-(3,5-ditributyl-4-hydroxyphenyl)propanoic acid n-octadecyl ester, triethylene glycol-bis[3-(3-three) Grade butyl-5-methyl-4-hydroxyphenyl)-propionate], tetrakis[methylene-3-(3,5-bis-tris-butyl-4-hydroxyphenyl)-propionic acid Ester] methane, 2-tert-butylbutyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate, 2,2'-methylene Base-bis(4-methyl-6-tertiary butylphenol), 2,2'-thiobis(4-methyl-6-tertiary butylphenol), 2,2'-thio-bia Ethyl-bis[3-(3,5-bistris-butyl-4-hydroxyphenyl)propionate] or 2,2'-ethylenediamine-bis[ethyl-3-(3,5) -Bis-tertiary butyl-4-hydroxyphenyl)propionate].

Specific examples of the thioether-based antioxidant are: distearyl thiodipropionate, dipalmitoside dipropionate, pentaerythritol-tetra-(β-dodecyl-thiopropionate) or Dioctadecyl sulfide and the like.

Phosphorus-based antioxidants such as, but not limited to, phosphorous acids, phosphoric acids, phosphinic acids, phosphonic acids, phosphites, phosphates, phosphonites, phosphonates, tertiary phosphines, triorganic Phosphate or acid phosphate compound. Among the above phosphorus-based antioxidants, a compound of a phosphorous acid, a phosphoric acid, a phosphinic acid, a phosphonic acid, a triorganophosphoric acid ester or an acidic phosphate ester is particularly preferable. Further, in the acidic phosphate compound, the organic group also contains a mono-, di-, or poly-substitution. The compounds exemplified below may be used singly or in combination.

Triorganophosphate compounds such as, but not limited to, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tridecyl phosphate, tridodecyl phosphate, three Lauryl phosphate, three Stearyl phosphate, tricresyl phosphate, triphenyl phosphate, trichlorophenyl phosphate, diphenyl cresyl phosphate, diphenyl mono-o-phenyl phosphate, tris (butyl) Oxyethyl) ester and the like. Preferably, the triorganophosphate compound is a trialkyl phosphate compound; more preferably, the three alkyl phosphate compounds have a carbon number of 1 to 22; more preferably, the carbon number is 1 to 4. Most preferably, the trialkyl phosphate compound is trimethyl phosphate.

Acid phosphate compounds such as, but not limited to, methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, butoxy ethyl acid phosphate, octyl acid phosphate, sulfhydryl acid phosphate, laurel Acid phosphate, stearyl acid phosphate, oleyl acid phosphate, behenyl acid phosphate, phenyl acid phosphate, nonylphenyl acid phosphate, cyclohexyl acid phosphate, phenoxy Ethyl acid phosphate, alkoxy polyethylene glycol acid phosphate or bisphenol A acid phosphate. Among the above acidic phosphate compounds, a long-chain dialkyl acid phosphate having a carbon number of 10 or more can effectively improve the (meth) acrylate-styrene copolymer composition in addition to high thermal stability. Thermal stability.

Phosphite compounds such as, but not limited to, triphenyl phosphite, tris(nonylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, tris (octadecyl) sub Phosphate, dimercaptophenyl phosphite, dioctylphenyl phosphite, diisopropylphenyl phosphite, butyl diphenyl phosphite, decyl diphenyl phosphite, xin Diphenyl phosphite, tris(diethylphenyl) phosphite, tris(diisopropylphenyl) phosphite, tris(di-n-butylphenyl) phosphite, three (2, 4-tertiary butylphenyl)phosphite, tris(2,6-ditributylphenyl)phosphite, distearyl pentaerythritol Diphosphite, bis(2,4-ditributylphenyl)neopentanol diphosphite, bis(2,6-ditributyl-4-methylphenyl)nepentaerythritol Alcohol diphosphite, bis(2,6-ditributyl-4-ethylphenyl)neopentanol diphosphite, bis{2,4-bis(1-methyl-1-benzene) Ethyl ethyl) phenyl} neopentyl alcohol diphosphite, phenyl bisphenol A neopentyl alcohol diphosphite, bis(nonylphenyl) pentaerythritol diphosphite, dicyclohexyl neo Pentaerythritol diphosphite, and the like.

The slip agent can be used singly or in combination, for example but not limited to: (1). Metal soap: calcium stearate, magnesium stearate, lithium stearate, etc.; (2). Compound: ethylene distearin Amine (ethylene bis (stearamide), referred to as EBS), methylene distearylamine, decyl palmitate, butyl stearate, palmitate stearate, polypropionate tristearate, pentaerythritol stearin An acid ester, n-docosic acid, stearic acid or stearyl alcohol; (3) wax: polyethylene wax, octadecanoic acid wax, carnauba wax or petroleum wax. The total amount of the (meth) acrylate-styrene copolymer is 100 parts by weight, and the content of the slip agent is in the range of 0.03 to 5.0 parts by weight.

The processing aid can improve extrusion moldability and thermoformability, and can use, for example, an acrylate-based processing aid or a core-shell type processing aid having a weight average molecular weight of 500,000 or more. Used alone or in combination.

The ultraviolet absorber may be used singly or in combination, and examples thereof include, but are not limited to, a Benzotriazole-based compound, a Benzophenone-based compound, and a cyanoacrylic acid-based compound.

The UV stabilizer can be used alone or in combination, for example but not It is limited to: a hindered amine compound or the like.

The processing aid, the ultraviolet absorber, and the ultraviolet stabilizer are used in an amount of from 0.02 to 2.0 parts by weight per 100 parts by weight of the total of the (meth)acrylate-styrene copolymer.

The charge preventing agent can be used singly or in combination, and is not limited to, for example, a low molecular weight compound such as a tertiary amine compound or a quaternary ammonium salt compound, or a polymer having a permanent charge prevention property such as polyamine polyether.

The fillers can be used singly or in combination, such as, but not limited to, calcium carbonate, alumina, mica, and the like.

The reinforcing agent can be used singly or in combination, such as, but not limited to, glass fiber, carbon fiber, various whiskers, and the like.

The colorant can be used singly or in combination, such as, but not limited to, titanium oxide, iron oxide, graphite, phthalocyanine dye, and the like.

The heat stabilizer can be used singly or in combination, such as, but not limited to, dibutyltin maleate, a basic magnesium aluminum hydroxycarbonate, and the like.

The thermochromic preventing agent can be used singly or in combination, such as, but not limited to, a low molecular weight styrene-anhydrous maleic acid copolymer.

The preparation of the (meth) acrylate-styrene copolymer composition of the present invention is not particularly limited, and a (meth) acrylate-styrene copolymer prepared in advance and an inner ring bisphenol amide can be used. The phosphate compound can be kneaded uniformly, and a method of directly polymerizing a (meth) acrylate monomer, a styrene monomer, and an inner ring bisphenol phosphite compound can also be employed. The mixing and kneading of the raw material components is not limited in the order, and a general mixing and kneading machine may be used. Mixing mixers such as, but not limited to, Brabender plastometers, Banbury mixing Machine, kneading-mixer, roller press, single-axis or two-axis extruder. Preferably, the (meth) acrylate-styrene copolymer composition is prepared by mixing and kneading by an extruder or the like, and then cooling the condensed product and granulating it. Preferably, the (meth) acrylate-styrene copolymer composition is mixed and kneaded at a temperature ranging from 160 ° C to 280 ° C, more preferably from 180 ° C to 250 ° C. The embodiment of the present invention is a method described in the latter, that is, a mixed (meth) acrylate monomer, a styrene monomer inner ring bisphenol phosphite compound, and a direct polymerization method (methyl). An acrylate-styrene copolymer composition.

The use of the (meth) acrylate-styrene copolymer composition of the present invention is not particularly limited, and may be formulated to have properties such as high fluidity or high heat stability depending on the demand for the subsequent preparation of the molded article. The molded article of the present invention is obtained from the (meth) acrylate-styrene copolymer composition described above, and can be various molded articles obtained by injection molding or compression molding, or A molded article obtained by extrusion molding, blow molding, thermoforming, vacuum molding, or hollow molding, and specific examples thereof are optical grade sheets, film molded articles, and the like.

The present invention will be further illustrated by the following examples, but it should be understood that this embodiment is intended to be illustrative only and not to be construed as limiting.

<Example>

[Examples 1 to 2 and Comparative Example 1]

The polymerization apparatus of Preparation Examples 1 to 2 and Comparative Example 1 comprises a fully mixed reactor, a plurality of laminar flow reactors, and a devolatilization Set. In order to clearly illustrate the preparation process, the following description is made with reference to Example 1, and the remaining examples and comparative examples were prepared in the same manner.

According to the types and amounts of the components of Table 1, each component was continuously fed into the fully mixed reactor for continuous solution polymerization, and the reaction temperature was maintained at 100 ° C and the pressure was 600 torr. The mixture was thoroughly stirred in the fully mixed reactor to uniformly mix the components to form a reactant, and after standing for about 3.5 hours, the reactant was continuously fed into the laminar flow reactor. In the laminar flow reactor, the reaction temperature was ramped from 160 ° C to 160 ° C, and a polymer solution was formed after about 5 hours of residence. Then, the polymer solution is sent to the devolatilizer, the polymer solution is heated to 235 ° C, and the polymer solution is subjected to a devolatilization step under reduced pressure to obtain the methacrylic acid of Example 1. An ester-styrene copolymer composition.

Then, the (meth) acrylate-styrene copolymer composition of Example 1 was formed into a single piece by an extrusion apparatus, and the strip was cooled and pelletized to prepare Example 1 A plastic particle of a (meth) acrylate-styrene copolymer composition.

[evaluation project]

Melt flow index (MI):

The (meth) acrylate-styrene copolymer compositions of Examples 1 to 2 and Comparative Example 1 were measured in accordance with ASTM D1238 (measurement conditions: temperature: 200 ° C, load: 5 kg). Unit: g/10 minutes (g/10min.).

Softening point temperature (Vicat softening temp., SP for short):

The (meth) acrylates of Examples 1 to 2 and Comparative Example 1 were used. The styrene copolymer composition was measured in accordance with ASTM D1525 (measurement conditions: heating rate was 50 ° C per hour, load 1 kg). Unit: °C.

Glass transition temperature (T _g )

The (meth)acrylate-styrene copolymer compositions of Examples 1 to 2 and Comparative Example 1 were measured by a differential scanning calorimeter (DSC). Unit: °C.

Long light path (yel value):

The (meth)acrylate-styrene copolymer compositions of Examples 1 to 2 and Comparative Example 1 were prepared into test pieces (220 mm × 20 mm × 3 mm), and then separated by a long optical path. (NIPPON DENSHOKU ASA-1) The test piece was measured.

Long light path luminance (L)

The (meth)acrylate-styrene copolymer compositions of Examples 1 to 2 and Comparative Example 1 were prepared into test pieces (220 mm × 20 mm × 3 mm), and then separated by a long optical path. (NIPPON DENSHOKU ASA-1) The test piece was measured.

Penetration (T%)

The composition of the (meth) acrylate-styrene copolymer of Examples 1 to 2 and Comparative Example 1 was made into a disk test piece (diameter: 55 mm × thickness: 3 mm), and then a haze meter (Haze) Meter NDH 2000) Measure the original test piece.

Tensile strength

The (meth) acrylate-styrene copolymer compositions of Examples 1 to 2 and Comparative Example 1 were measured in accordance with ASTM D638 (measurement conditions: elongation of 6 mm per minute). Unit: kg/cm ² .

Oligomer content

The (meth)acrylate-styrene copolymer compositions of Examples 1 to 2 and Comparative Example 1 were measured by Gas Chromatography (GC). Unit: ppm.

a: The amount is calculated as 100% by weight based on the total amount of the monomer mixture; b: The amount is calculated based on 100 parts by weight of the total amount of the monomer mixture.

c: the content is calculated as 100% by weight based on the total amount of the (meth) acrylate-styrene copolymer; d: the content is 100 based on the total amount of the (meth) acrylate-styrene copolymer Calculated by weight.

As shown by the results of Table 2, the (meth) acrylate-styrene copolymer compositions of Examples 1 and 2 have the following characteristics: (1). It has a preferable melt coefficient and is advantageous for subsequent processing; (2). With appropriate softening Point temperature helps to increase thermal stability; (3) good brightness and penetration, which can make the subsequently obtained molded articles have good optical properties; (4). The tensile strength is good. In particular, the performance of Example 1 is superior to that of Comparative Example 1, and the molded article obtained later can have better mechanical strength; (5). Compared with Comparative Example 1, the inner ring bisphenol phosphorous acid is used. An ester compound which has a better yellowness without affecting the advantages of the above (1) to (4); (6) a low molecular weight oligomer (oligomer), and examples 1 and 2 ( The oligomer content in the methyl acrylate-styrene copolymer composition ranges from 1,500 ppm to 3,500 ppm, and therefore, has a preferable yellowness and does not cause mold contamination during injection molding.

In summary, the (meth) acrylate-styrene copolymer of the present invention comprises 40% by weight to 70% by weight of (meth) acrylate monomer units, and 30% by weight to 60% by weight of benzene. The vinyl monomer unit has the advantages of both polystyrene and poly(meth) acrylate, so that the (meth) acrylate-styrene copolymer composition has good processability and thermal stability. Further, an internal ring bisphenol phosphite compound having a content of 0.01 to 0.3 parts by weight is blended, so that the molded article obtained by using the (meth) acrylate-styrene copolymer composition has low yellowness and highness. Advantages of brightness, high penetration and good mechanical strength.

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the patent application scope and patent specification content of the present invention, All remain within the scope of the invention patent.

Claims (10)

A (meth) acrylate-styrene copolymer composition comprising: a (meth) acrylate-styrene copolymer comprising 40% by weight to 70% by weight of a (meth) acrylate series a bulk unit, and 30% by weight to 60% by weight of a styrene monomer unit; and an inner ring bisphenol phosphite compound having a structure represented by the following formula (I) In the formula (I), R ¹ to R ⁴ each independently represent a C ₁ to C ₁₀ linear alkyl group or a C ₁ to C ₁₀ branched alkyl group, and R ⁵ represents a C ₁ to C ₃₀ linear alkyl group. or a C ₁ to C ₃₀ branched alkyl, R ⁶ is represented by H, C straight chain alkyl group or a C ₁ to C ₄ branched alkyl group of ₁ to C _4, and with (meth) acrylic acid ester - The total amount of the styrene-based copolymer is 100 parts by weight, and the content of the inner ring bisphenol phosphite compound ranges from 0.01 to 0.3 parts by weight. The (meth) acrylate-styrene copolymer composition according to claim 1, wherein the (meth) acrylate-styrene copolymer comprises 40% by weight to 50% by weight (A) An acrylate monomer unit, and 50% by weight to 60% by weight of a styrene monomer unit. (Meth) acrylate-styrene copolymer as claimed in claim 1 In the composition, the content of the inner ring bisphenol phosphite compound is from 0.01 to 0.15 parts by weight based on 100 parts by weight of the total of the (meth) acrylate-styrene copolymer. The (meth) acrylate-styrene copolymer composition according to claim 1, wherein the inner ring is 100 parts by weight based on the total amount of the (meth) acrylate-styrene copolymer. The content of the bisphenol phosphite compound ranges from 0.04 to 0.12 parts by weight. The (meth) acrylate-styrene copolymer composition according to claim 1, wherein the inner ring bisphenol phosphite compound is 2,2'-methylene bis (4,6-di) Tert-butyl phenyl) octyl phosphite. The (meth) acrylate-styrene copolymer composition according to claim 1, wherein the (meth) acrylate-styrene copolymer composition has an oligomer content of 500 ppm. Up to 5000 ppm. The (meth) acrylate-styrene copolymer composition according to claim 1, further comprising an antioxidant, and the antioxidant is contained in an amount ranging from 0.005 to 2.0 parts by weight. The (meth) acrylate-styrene copolymer composition according to claim 7, wherein the antioxidant is 3-(3,5-ditributyl-4-hydroxyphenyl)propionic acid. Octadecanol ester. The (meth) acrylate-styrene copolymer composition according to claim 1, further comprising pentaerythritol stearate, and the pentaerythritol stearate is contained in an amount ranging from 0.03 to 5.0 parts by weight. A molded article formed of the (meth)acrylate-styrene copolymer composition according to any one of claims 1 to 9.